body {
    height: 100vh;
    width: 100%;
    margin: 0;
    padding: 0;
}

header {
    position: absolute;
    left: 0;
    top: 0;
    right: 0;
    height: 29px;
    width: 100%;
}

footer {
    position: absolute;
    height: 29px;
    left: 0;
    bottom: 0;
    right: 0;
    vertical-align: bottom;
}

/* AI助手悬浮按钮样式 */
.ai-float-button {
    position: fixed;
    right: 20px;
    bottom: 20px;
    width: 60px;
    height: 60px;
    border-radius: 50%;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    font-size: 28px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
    transition: all 0.3s ease;
    z-index: 1000;
    user-select: none;
}

.ai-float-button:hover {
    transform: scale(1.1);
    box-shadow: 0 6px 25px rgba(0, 0, 0, 0.4);
}

.ai-float-button:active {
    transform: scale(0.95);
}